144 ci carb spacer to manifold bolts

I have a 144 ci engine, and i'm wondering what the thread is for the bolts that hold the carb spacer to the intake manifold. Standard threads don't work, and metric doesn't either.

american bolts come in coarse and fine thread.it won't be metric.

The bolts that hold the spacer to the manifold are coarse [USS , NC or UNC] thread - 5/16" or 3/8" , I don't recall which . If the threads are rusty or damaged , you may need to run a tap through . Describe the problem ; won't go in ? , go in but loose ? Just for reference the upper part of studs in the spacer is 5/16" fine [SAE , NF or UNF] thread .

Brand new bolts. The thread pitch in the intake manifold is something other than standard, or metric. Whatever it is, it is coarse, but none of my bolts are threading after two, or three turns.

Then the threads are either gunked up or stripped out. The '63 170 I have has the same head and it's a standard size...I just can't remember which one it is.

I was just really stoned. The bolts seem to fit now. Ha!